Clearly you're not following the argument. The argument presented was:
"It undermines most of beholder lore, which relies on them selectively using specific eye rays for effects like boring out lairs, charming minions, operating levers etc. In fact the beholder write-up specifically mentions digging with disintegrate."
In short:
I. The MM lore specifically says they dig out lairs, charm minions, etc.
II. Random eye-rays prevent them from doing any of that.
III. Ergo, random eye-rays need to go.
I just pointed out that (II) doesn't hold.
II holds just fine. Beholders are prevented from doing what they want to do when they want to do it and have to wait in 5E for pure chance to allow them. The logic is sound, it's your desire to keep a dumb new rule in 5E that prevents you from removing it. But that's your business at your table. As many posters have posted here, random eye rays are a stupid new invention that Beholder Lore never had in the past.
Eye Rays (Su): Each of a beholder's small eyes can produce a magical ray once per round as a free action. During a single round, the beholder can only aim three eye rays at targets in any one 90-degree arc (up, forward, backward, left, right, or down.) The remaining eyes must aim at targets in other arcs, or not at all. A beholder can tilt and pan its body each round to change which rays it can bring to bear in any given arc.
Beholders were always able to control their eyestalks. In every edition of the game. You like this new rule, fine. Use it. But don 't try to justify it as "beholder lore". It is nothing of the sort. Beholders were never handcuffed like this.
In fact, Beholders were never handcuffed to only three eyestalk attacks per round. That's REALLY restrictive. 5E Beholders are wimps compared to earlier versions.
Getting back on topic, why not just have the Beholders bust holes through the ship and retreat? Darkness has a limited duration. Let the enemies use up their Darkness spells and then kick their butts at a place and time of the Beholders' choosing? Why stay and fight? Why come up with special tactics for an unexpected foe when the Beholder can just wait them out? Beholders are intelligent, they do not need to have bizarre special mirror or sheet or other tactics prepared ahead of time for Darkness wielding foes. They just need to attack their foes when they are not ready for it.
Darkness foe invades. Beholder flees and sets up ambush. If it cannot flee, it uses its antimagic ray to prevent the nasty stuff from hitting it until it gets the opportunity to disintegrate a hole through the ship and flee. No muss. No fuss. No "I went to the forums and had 50 other people scratch their heads trying to come up with cool ideas on how my wimpy beholders were going to overcome a simple level 2 Darkness spell". The fact that you came here looking for help (and you got very few solid non-way out in left field suggestions on how to do this) should suggest to you that there are serious design flaws in the 5E beholder, but play them as written if you want.
Btw, the easiest way for Beholders to attack foes is via intersecting tunnels that run in all directions in a Beholder lair. In a dark lair, it is easy to have a 3D mazie of tunnels that Beholders can zip around in, but the vast majority of other creatures which cannot hover and change direction easily in flight (or without flight) cannot. Hit and run tactics where foes never see them coming and by the time they react, the Beholder is already gone (i.e. move, attack, move). Beholders should rarely fight in a straight up fight.
Last edited: